Tool coupler with threaded connection for top drive

ABSTRACT

A drive unit includes a drive stem having first friction surfaces and a load coupling, wherein the load coupling is a threaded coupling. The drive unit also includes a transmission unit having second friction surfaces parallel to the first friction surfaces; and shoulders proximate a bottom of the transmission unit. The drive unit further includes a transmission selector movable to an “on” position or an “off” position, wherein the drive stem moves synchronously with the transmission unit when the transmission selector is in the “on” position.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of U.S. patent applicationSer. No. 15/457,572, filed Mar. 13, 2017, which is incorporated byreference.

BACKGROUND OF THE INVENTION

Embodiments of the present invention generally relate to equipment andmethods for coupling a top drive to one or more tools. The coupling maytransfer both axial load and torque bi-directionally from the top driveto the one or more tools.

A wellbore is formed to access hydrocarbon-bearing formations (e.g.,crude oil and/or natural gas) or for geothermal power generation by theuse of drilling. Drilling is accomplished by utilizing a drill bit thatis mounted on the end of a tool string. To drill within the wellbore toa predetermined depth, the tool string is often rotated by a top driveon a drilling rig. After drilling to a predetermined depth, the toolstring and drill bit are removed, and a string of casing is lowered intothe wellbore. Well construction and completion operations may then beconducted.

During drilling and well construction/completion, various tools are usedwhich have to be attached to the top drive. The process of changingtools is very time consuming and dangerous, requiring personnel to workat heights. The attachments between the tools and the top drivetypically include mechanical, electrical, optical, hydraulic, and/orpneumatic connections, conveying torque, load, data, signals, and/orpower.

Typically, sections of a tool string are connected together withthreaded connections. Such threaded connections are capable oftransferring load. Right-hand (RH) threaded connections are also capableof transferring RH torque. However, application of left-hand (LH) torqueto a tool string with RH threaded connections (and vice versa) risksbreaking the string. Methods have been employed to obtain bi-directionaltorque holding capabilities for connections. Some examples of thesebi-directional setting devices include thread locking mechanisms forsaver subs, hydraulic locking rings, set screws, jam nuts, lock washers,keys, cross/thru-bolting, lock wires, clutches and thread lockingcompounds. However, these solutions have shortcomings. For example, manyof the methods used to obtain bi-directional torque capabilities arelimited by friction between component surfaces or compounds thattypically result in a relative low torque resistant connection. Lockingrings may provide only limited torque resistance, and it may bedifficult to fully monitor any problem due to limited accessibility andlocation. For applications that require high bi-directional torquecapabilities, only positive locking methods such as keys, clutches orcross/through-bolting are typically effective. Further, some highbi-directional torque connections require both turning and millingoperations to manufacture, which increase the cost of the connectionover just a turning operation required to manufacture a simplemale-to-female threaded connection. Some high bi-directional torqueconnections also require significant additional components as comparedto a simple male-to-female threaded connection, which adds to the cost.

Safer, faster, more reliable, and more efficient connections that arecapable of conveying load, data, signals, power and/or bi-directionaltorque between the tool string and the top drive are needed.

SUMMARY OF THE INVENTION

The present invention generally relates to equipment and methods forcoupling a top drive to one or more tools. The coupling may transferboth axial load and torque bi-directionally from the top drive to theone or more tools.

In an embodiment, a drive unit of a top drive system includes a drivestem having a torque gear profile and a load coupling, wherein the loadcoupling is a threaded coupling; and a torque sleeve movable between afirst position and a second position, and having a sleeve gear profilethat engages the torque gear profile when the torque sleeve is in thesecond position.

In an embodiment, a method of coupling a drive unit to a tool adapterincludes positioning the tool adapter below the drive unit; rotating adrive stem of the drive unit to make up a threaded coupling with a toolstem of the tool adapter; and moving a torque sleeve of the drive unitto engage both a torque gear profile of the drive stem and a stem gearprofile of the tool stem.

In an embodiment, a drive unit of a top drive system includes a drivestem having a load coupling that is a threaded coupling; a spindle unitcomprising: an interior through which the drive stem extends; a counternut having a first guide profile mated with a second guide profile onthe drive stem; and a spindle having threading mated with threading onthe counter nut; and an annular motor operationally coupled to thespindle unit.

In an embodiment, a method of coupling a drive unit to a tool adapterincludes positioning the tool adapter below the drive unit; rotating adrive stem of the drive unit to make up a threaded coupling with a toolstem of the tool adapter; and rotating a spindle unit relative to thedrive stem to contact a counter nut of the spindle unit with the toolstem.

In an embodiment, a drive unit of a top drive system includes a drivestem having first friction surfaces and a load coupling, wherein theload coupling is a threaded coupling; a transmission unit having: secondfriction surfaces parallel to the first friction surfaces; and shouldersproximate a bottom of the transmission unit; and a transmission selectormovable to an “on” position or an “off” position, wherein the drive stemmoves synchronously with the transmission unit when the transmissionselector is in the “on” position.

In an embodiment, a method of coupling a drive unit to a tool adapterincludes positioning the tool adapter below the drive unit so thatshoulders of a transmission unit of the drive unit align with shouldersof a tool stem of the tool adapter; and rotating a drive stem of thedrive unit to make up a threaded coupling with the tool stem, wherein:the drive stem and the transmission unit rotate together during thepositioning of the tool adapter; and the drive stem and the transmissionunit do not rotate together during the making up of the threadedcoupling.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features of the presentinvention can be understood in detail, a more particular description ofthe invention, briefly summarized above, may be had by reference toembodiments, some of which are illustrated in the appended drawings. Itis to be noted, however, that the appended drawings illustrate onlytypical embodiments of this invention and are therefore not to beconsidered limiting of its scope, for the invention may admit to otherequally effective embodiments.

FIG. 1 illustrates a drilling system, according to embodiments of thepresent disclosure.

FIG. 2 illustrates a top drive system of the drilling system of FIG. 1.

FIGS. 3A-3B illustrates a drive stem of the top drive system of FIG. 2.

FIGS. 4A-4B illustrates a torque sleeve of the top drive system of FIG.2.

FIGS. 5A-5B illustrates a tool stem of the top drive system of FIG. 2.

FIGS. 6A-6C illustrate coupling between a drive unit and a tool adapterof the top drive system of FIG. 2.

FIG. 7 illustrates a top drive system of the drilling system of FIG. 1.

FIGS. 8A-8B illustrates a spindle unit of the top drive system of FIG.7.

FIGS. 9A-9C illustrate coupling between a drive unit and a tool adapterof the top drive system of FIG. 7.

FIG. 10 illustrates a top drive system of the drilling system of FIG. 1.

FIG. 11 illustrates a transmission unit of the top drive system of FIG.10.

FIGS. 12A-12B illustrates a selection ring of the top drive system ofFIG. 10.

FIGS. 13A-13E illustrate coupling between a drive unit and a tooladapter of the top drive system of FIG. 10.

DETAILED DESCRIPTION

The present invention provides equipment and methods for coupling a topdrive to one or more tools. The coupling may transfer torquebi-directionally from the top drive to the one or more tools. Thecoupling may provide mechanical, electrical, optical, hydraulic, and/orpneumatic connections. The coupling may conveying torque, load, data,signals, and/or power. For example, axial loads of tool strings may beexpected to be several hundred tons, up to, including, and sometimessurpassing 750 tons. Required torque transmission may be tens ofthousands of foot-pounds, up to, including, and sometimes surpassing 100thousand foot-pounds. Embodiments disclosed herein may provide axialconnection integrity, capable of supporting high axial loads, goodsealability, resistance to bending, high flow rates, and high flowpressures.

Some of the many benefits provided by embodiments of this disclosureinclude a reliable method to transfer full bi-directional torque,thereby reducing the risk of accidental breakout of threaded connectionsalong the tool string. Embodiments of this disclosure also provide afast, hands-free method to connect and transfer power from the driveunit to the tool adapter. Embodiments provide automatic connection forpower and data communications.

In some embodiments, the torque transfer path from the top drive systemto the tool string bypasses the threaded connection between the driveunit and the tool adapter. This may allow full bi-directional torque tobe applied in the tool string. This compares to systems wherein thetorque transfer path proceeds through the threaded connections betweenthe drive unit and the tool adapter which present a risk of backing outthe main threaded connection while rotating in the breakout direction.

FIG. 1 illustrates a drilling system 1, according to embodiments of thepresent disclosure. The drilling system 1 may include a drilling rigderrick 3 d on a drilling rig floor 3 f. As illustrated, drilling rigfloor 3 f is at the surface of a subsurface formation 7, but thedrilling system 1 may also be an offshore drilling unit, having aplatform or subsea wellhead in place of or in addition to rig floor 3 f.The derrick may support a hoist 5, thereby supporting a top drive 4. Insome embodiments, the hoist 5 may be connected to the top drive 4 bythreaded couplings. The top drive 4 may be connected to a tool string 2.At various times, top drive 4 may support the axial load of tool string2. In some embodiments, the top drive 4 may be connected to the toolstring 2 by threaded couplings. The rig floor 3 f may have an openingthrough which the tool string 2 extends downwardly into a wellbore 9. Atvarious times, rig floor 3 f may support the axial load of tool string2. During operation, top drive 4 may provide torque to tool string 2,for example to operate a drilling bit near the bottom of the wellbore 9.The tool string 2 may include joints of drill pipe connected together,such as by threaded couplings. At various times, top drive 4 may provideright hand (RH) torque or left hand (LH) torque to tool string 2, forexample to make up or break out joints of drill pipe. Power and/orsignals may be communicated between top drive 4 and tool string 2. Forexample, pneumatic, hydraulic, electrical, optical, or other powerand/or signals may be communicated between top drive 4 and tool string2. The top drive 4 may include a control unit, a drive unit, and a tooladapter. In some embodiments, the tool adapter may utilize threadedconnections. In some embodiments, the tool adapter may be a combinedmulti-coupler (CMC) or quick connector to support load and transfertorque with couplings to transfer power (hydraulic, electric, data,and/or pneumatic).

FIG. 2 illustrates a top drive system 100 (e.g., top drive 4 in FIG. 1)according to embodiments described herein. Generally, top drive system100 includes a drive unit 110 and a tool adapter 150. The drive unit 110generally includes a housing 120, becket 125, drive gears 130, motors140 (e.g., electric or hydraulic motors), first portions of one or morecouplings 170, a drive stem 180, and a torque sleeve 190. Becket 125 mayconvey load from the top drive system 100 to the hoist 5. Becket 125 maybe used with, or replaced by, other load-transfer components. Drivegears 130 may couple to motors 140 by way of shaft 135. Drive gears 130may convey torque between the motors 140 and the drive stem 180. Asillustrated, top drive system 100 includes two drive gears 130 (only oneshown in FIG. 2) and two motors 140. Any number of drive gears 130and/or motors 140 may be considered to accommodate manufacturing andoperational conditions. The motors 140 may be fixed relative to thehousing 120. The drive stem 180 may extend through an interior of torquesleeve 190. The tool adapter 150 generally includes a tool stem 160 andsecond portions of the couplings 170. Couplings 170 may includecomplementary components disposed in or on drive unit 110 and tooladapter 150. The tool stem 160 generally remains below the drive unit110. (It should be understood that “below”, “above”, “vertically”, “up”,“down”, and similar terms as used herein refer to the generalorientation of top drive 4 as illustrated in FIG. 1. In some instances,the orientation may vary somewhat, in response to various operationalconditions. In any instance wherein the central axis of the top drivesystem is not aligned precisely with the direction of gravitationalforce, “below”, “above”, “vertically”, “up”, “down”, and similar termsshould be understood to be along the central axis of the top drivesystem.) The tool stem 160 connects the top drive system 100 to the toolstring 2. The tool stem 160 and drive stem 180 may share a central bore165 (e.g. providing fluid communication through the top drive system 100to the tool string 2). Couplings 170 may include, for example, threadedcouplings, hydraulic couplings, pneumatic couplings, electroniccouplings, fiber optic couplings, power couplings, data couplings,and/or signal couplings. When the drive unit 110 is coupled to the tooladapter 150, top drive system 100 may transfer bi-directional torque,load, power, data, and/or signals between the top drive and the tool.

As illustrated in FIG. 3, drive stem 180 may have two gear profiles:drive gear profile 185 and torque gear profile 195. Drive gears 130(FIG. 2) may engage drive stem 180 at drive gear profile 185. Motors 140may turn shaft 135, which turns drive gears 130, thereby turning drivegear profile 185 and drive stem 180. Drive gear profile 185 may haveteeth designed to mesh with the gearing of drive gears 130.Alternatively, drive gears 130 and/or drive gear profile 185 may beconfigured to engage belt drive, chain drive, or other systems that arecapable of conveying rotation. Also illustrated in FIG. 3, the drivestem 180 may be encircled by swivel 174, centering ring 181, and/or sealsleeve 182. The centering ring 181 may provide rigidity to theconnection, for example, resisting bending forces. The centering ring181 may assist in alignment of seals, couplers, and/or data connectors.For example, the centering ring 181 may provide for proper alignmentbetween the drive stem 180 and the seal package 163 (FIG. 5B) of thetool stem 160. The fit between the centering ring 181 and the tool stem160 may control or reduce play between the components, thereby improvingthe sealing performance. The coupling between drive stem 180 and sealsleeve 182 may include a threaded coupling 183 and/or one or moreO-rings 184. The O-rings 184 may engage the inner diameter of the sealsleeve 182 to reduce or prevent high pressure fluid leakage out of theconnection. The seal sleeve 182 may be incorporated as a replaceablecomponent of the drive unit 110. Also illustrated in FIG. 3, a portionof the exterior of drive stem 180 may include a threaded coupling 186.As illustrated, threaded coupling 186 is disposed between centering ring181 and torque gear profile 195, but threaded coupling 186 may also bedisposed at other locations along the length of drive stem 180. When thedrive unit 110 is coupled to the tool adapter 150, threaded coupling 186may provide a load coupling between drive stem 180 and tool stem 160.Threaded coupling 186 may be a heavy-load capacity thread (e.g., stubacme thread).

As illustrated in FIG. 4A, at least a portion of the interior of torquesleeve 190 may include a sleeve gear profile 192. Sleeve gear profile192 may engage torque gear profile 195 when torque sleeve 190 is in alowered position (shown in FIG. 6C). When torque sleeve 190 is in alowered position, drive stem 180 may turn torque gear profile 195, whichengages sleeve gear profile 192, thereby turning torque sleeve 190.

As illustrated in FIG. 5A, tool stem 160 may have a stem gear profile162 on at least a portion of an exterior surface near the top of thetool stem 160. Sleeve gear profile 192 may engage stem gear profile 162when torque sleeve 190 is in a lowered position (shown in FIG. 6C). Whentorque sleeve 190 is in a lowered position, drive stem 180 may turntorque gear profile 195, which engages sleeve gear profile 192, whichengages stem gear profile 162, thereby turning tool stem 160. Asillustrated in FIG. 5B, tool stem 160 may have a seal package 163disposed in the central bore 165. When the drive unit 110 is coupled tothe tool adapter 150, the seal package 163 may provide a seal of thecentral bore 165 between the drive stem 180 and the tool stem 160. Theseal package 163 may be located adjacent to a shoulder 164 or in arecess (not shown) of the interior of tool stem 160. The seal packagemay include high pressure-high temperature (HPHT) dynamic seals. Forexample, the seal package may seal the central bore 165 up to pressuresof about 15 k psi. Also illustrated in FIG. 5B, tool stem 160 may have athreaded coupling on at least a portion of an interior surface near thetop of the tool stem 160.

Drive unit 110 may be coupled to tool adapter 150 in order to transferbi-directional torque, load, power, data, and/or signals between the topdrive and the tool. Coupling of drive unit 110 to tool adapter 150 mayproceed as a multi-step process. In one embodiment, as illustrated inFIGS. 6A-6B, the coupling begins with axial load coupling between drivestem 180 and tool stem 160. Drive stem 180 may be aligned with tool stem160 so that a lower portion of drive stem 180 may be stabbed into toolstem 160. For example, drive stem 180 may be lowered relative to toolstem 160, and/or tool stem 160 may be raised relative to drive stem 180.Drive stem 180 may rotate relative to tool stem 160 so that threadedcoupling 186 on drive stem 180 engage and mate with threaded coupling166 on tool stem 160 (FIG. 6B). Threaded coupling 166 may be aheavy-load capacity thread (e.g., stub acme thread). An exterior surfaceof seal sleeve 182 may contact and/or engage with seal package 163.

Motors 140 may provide torque to make up or break out the axial loadconnection between tool stem 160 and drive stem 180. For example, motors140 may turn shaft 135, which turns drive gears 130, thereby turningdrive gear profile 185 and drive stem 180. Threaded coupling 186 ondrive stem 180 may engage and mate with threaded coupling 166 on toolstem 160. Torque of drive stem 180 may cause threading (or unthreading,depending on direction) between tool stem 160 and drive stem 180. Thedrive stem 180 may have RH male threading, while the tool stem 160 mayhave RH female threading. When tool stem 160 is coupled to drive stem180, as shown in FIG. 6B, axial load may be transferred between the topdrive and the tool. Likewise, when tool stem 160 is coupled to drivestem 180, central bore 165 may provide fluid communication between thetop drive and the tool. It should be appreciated that, when tool stem160 is coupled to drive stem 180, torque in the direction of thethreaded couplings 186/166 may also be transferred between the top driveand the tool. For example, torque may be transferred from the motors 140through shaft 135 to the drive gears 130, through drive gear profiles185 to the drive stem 180, through the threaded couplings 186/166, tothe tool stem 160, and to the tool string 2.

Coupling of drive unit 110 to tool adapter 150 may proceed withbi-directional torque coupling between torque sleeve 190 and tool stem160, as illustrated in FIGS. 6B-6C. The drive stem 180 may extendthrough an interior of torque sleeve 190. Torque sleeve 190 may movevertically relative to drive stem 180. For example, actuators 191 (e.g.,hydraulic or pneumatic cylinders, or electric actuators) on drive stem180 may move torque sleeve 190 between a raised position and a loweredposition. While tool stem 160 is load coupling with drive stem 180, asshown in FIGS. 6A-6B, torque sleeve 190 may be in the raised position(relative to drive stem 180). Torque sleeve 190 may then move to thelowered position (relative to drive stem 180; FIG. 6C) to engage toolstem 160, thereby transferring torque. For example, sleeve gear profile192 on an interior surface of torque sleeve 190 may engage torque gearprofile 195 of drive stem 180 when torque sleeve 190 is in the loweredposition (shown in FIG. 6C). Drive stem 180 may turn torque gear profile195 to engage sleeve gear profile 192, thereby turning torque sleeve190, and sleeve gear profile 192 may also engage stem gear profile 162,thereby turning tool stem 160.

Once torque sleeve 190 has moved to a lowered position and coupled totool stem 160, as shown in FIG. 6C, bi-directional torque may betransferred between the top drive and the tool. For example, torque gearprofile 195 of drive stem 180 may engage sleeve gear profile 192 oftorque sleeve 190, which, when in the lowered position, also engagesstem gear profile 162, thereby providing torque to tool stem 160 duringdrilling operations. Bi-directional torque may be thereby transferredfrom the motors 140 of the drive unit 110 to the tool stem 160, and thusto the tool string 2.

In some embodiments, coupling drive unit 110 to tool adapter 150 may befacilitated with various sensors, actuators, couplers, and/or adapters.For example, couplings 170 may include one or more hydraulic, pneumatic,electrical, or optical couplings, providing fluid, electrical, optical,signal, data, and/or power communication between the drive unit 110 andthe tool adapter 150. Couplings 170 may include tool stem connectors 171(FIG. 5B) and mating torque sleeve connectors 172 (FIG. 4B). connectors171/172 may communicate signals (e.g., hydraulic, pressure, fluid, data,optical, electrical, etc.) from the drive unit 110 to the tool adapter150. Alternatively, connectors 172 may be incorporated on drive stem180.

As another example, couplings 170 may include a swivel 174 (e.g., ahydraulic swivel or a pneumatic swivel) along drive stem 180. Swivel 174may be disposed co-axially with drive stem 180. Swivel 174 may encircledrive stem 180. In some embodiments, swivel 174 may be fixed relative tohousing 120 while allowing rotation between swivel 174 and drive stem180. In some embodiments, swivel 174 may be fixed relative to drive stem180 while allowing rotation between swivel 174 and housing 120. In someembodiments, swivel 174 may be free to rotate both relative to drivestem 180 and housing 120.

As another example, coupling drive unit 110 to tool adapter 150 may befacilitated with various sensors. The torque sleeve 190 may have sensors173 (FIG. 4B) located near its lower edge to ease the alignment processbetween the couplings 170 located on the drive unit 110 and matingcouplings 170 located on the tool adapter 150.

FIG. 7 illustrates an alternative top drive system 200 according toembodiments described herein. Except as noted, top drive system 200 isconfigured and functions similarly to top drive system 100. For example,top drive system 200 includes a drive unit 210 and a tool adapter 250.The drive unit 210 generally includes a housing 220, becket 225, drivegears 230, motors 240, first portions of one or more couplings 270, anda drive stem 280. Rather than torque sleeve 190, drive unit 210 includesa spindle unit 290. Rather than actuators 191, drive unit 210 includesan annular motor 291 (e.g., hydraulic or electric motor) operationallycoupled to components of the spindle unit 290. The drive stem 280 mayextend through an interior of spindle unit 290. In some embodiments, atleast a portion of the annular motor 291 may be fixed relative to thedrive stem 280. The tool adapter 250 generally includes a tool stem 260and second portions of the couplings 270. The tool stem 260 connects thetop drive system 200 to the tool string 2. The tool stem 260 and drivestem 280 may share a central bore 265. When the drive unit 210 iscoupled to the tool adapter 250, top drive system 200 may transferbi-directional torque, load, power, data, and/or signals between the topdrive and the tool.

As illustrated in FIG. 8A, spindle unit 290 generally includes annularmotor 291, a spindle 293, and a counter nut 294. The drive stem 280 mayextend through interiors of annular motor 291, spindle 293, and/orcounter nut 294. Annular motor 291 is configured to rotate spindle 293relative to drive stem 280. In some embodiments, a portion of annularmotor 291 is fixed to drive stem 280. In some embodiments, a portion ofannular motor 291 is rotationally coupled to spindle 293. An example ofa suitable annular motor is a 1 MB frameless, maintenance-freeasynchronous motor with high power density, available from Bosch RexrothAG of Lohr, Germany. In the illustrated embodiment, annular motor 291includes a fixed portion 291-f that is fixed to drive stem 280, and arotatable portion 291-r that is rotatable relative to drive stem 280. Asillustrated, rotatable portion 291-r is rotationally coupled to spindle293. For example, rotatable portion 291-r is coupled to a flange 292,which is coupled to spindle 293. In some embodiments, flange 292 andspindle 293 are permanently fixed together and/or formed as a unifiedcomponent. Annular motor 291 may thereby drive rotation in spindle 293by rotating rotatable portion 291-r relative to fixed portion 291-f. Inother embodiments, annular motor 291 includes gearing, wheels, tracks,etc., capable of conveying rotational motion (relative to drive stem280) to spindle 293. Counter nut 294 may move vertically relative todrive stem 280 and/or spindle 293 Annular motor 291 may provide torque,thereby rotating spindle 293 relative to drive stem 280. Spindle 293 mayhave internal threading, and counter nut 294 may have externalthreading, for example threading 294-t (FIG. 8B). Spindle 293 maythereby mate with and/or engage counter nut 294. Drive stem 280 may havean external guide profile proximate the spindle unit 290, and counternut 294 may have an internal guide profile, for example guide profile294-g (FIG. 8B). Counter nut 294 may thereby mate with and/or engagedrive stem 280. Engagement of the guide profiles may prevent rotationbetween counter nut 294 and drive stem 280. Also illustrated in FIG. 8A,a portion of the exterior of drive stem 280 may include a threadedcoupling 286.

As before, coupling of drive unit 210 to tool adapter 250 may proceed asa multi-step process. In one embodiment, illustrated in FIGS. 9A-9B, thecoupling begins with axial load coupling between drive stem 280 and toolstem 260. Drive stem 280 may be aligned with tool stem 260 so that alower portion of drive stem 280 may be stabbed into tool stem 260. Drivestem 280 may rotate relative to tool stem 260 so that threaded coupling286 on drive stem 280 engages and mates with threaded coupling 266 ontool stem 260 (FIG. 9B). Spindle unit 290 may remain fixed relative todrive stem 280 during axial load coupling. For example, annular motor291 may reduce or prevent rotation of spindle unit 290 relative to drivestem 280 during axial load coupling. Counter nut 294 may be in a raisedposition relative to drive stem 280 during axial load coupling.

Motors 240 may provide torque to make up or break out the axial loadconnection between tool stem 260 and drive stem 280. Torque of drivestem 280 may cause threading (or unthreading, depending on direction)between tool stem 260 and drive stem 280. Threaded coupling 286 of drivestem 280 may be RH male threading, while threaded coupling 266 of toolstem 260 may be RH female threading. When tool stem 260 is coupled todrive stem 280, as shown in FIG. 9B, axial load may be transferredbetween the top drive and the tool. Likewise, when tool stem 260 iscoupled to drive stem 280, central bore 265 may provide fluidcommunication between the top drive and the tool. It should beappreciated that, when tool stem 260 is coupled to drive stem 280,torque in the direction of the threaded couplings 286/266 may also betransferred between the top drive and the tool. For example, torque maybe transferred from the motors 240 through shaft 235 to the drive gears230, through drive gear profiles 285 to the drive stem 280, through thethreaded couplings 286/266, to the tool stem 260, and to the tool string2.

Coupling of drive unit 210 to tool adapter 250 may proceed withbi-directional torque coupling between drive stem 280 and tool stem 260,as illustrated in FIGS. 9B-9C. Annular motor 291 may rotate spindle 293relative to drive stem 280. Annular motor 291 may thereby rotate spindle293 relative to counter nut 294. Rotation of spindle 293 relative tocounter nut 294 may cause vertical motion of counter nut 294 due to thethreaded coupling between spindle 293 and counter nut 294 (e.g.,threading 294-t on counter nut 294) and the guided coupling betweendrive stem 280 and counter nut 294 (e.g., guide profile 294-g on counternut 294). During torque coupling, rotation of spindle 293 may continueuntil counter nut 294 contacts tool stem 260 (FIG. 9C). For example,counter nut 294 may contact shoulder 261 of tool stem 260. Shoulder 261may be proximate a top of tool stem 260. During operation, engagementbetween counter nut 294 and shoulder 261 may be maintained, for exampleby a locking mechanism (e.g., hydraulic), and/or by continued torquefrom annular motor 291. In some embodiments, rotation of drive stem 280in a direction (“loosening direction”) that would break up or loosen theconnection between threaded coupling 266 and threaded coupling 286 maythereby also force counter nut 294 downwards relative to drive stem 280.Once counter nut 294 contacts tool stem 260 (FIG. 9C), further rotationof drive stem 280 in the loosing direction may serve to transfer torqueto tool stem 260. Likewise, rotation of drive stem 280 in the oppositedirection (“tightening direction”) may serve to transfer torque to toolstem 260 through the connection of threaded coupling 266 with threadedcoupling 286.

De-coupling drive unit 210 from tool adapter 250 includes reverserotation of spindle 293. Annular motor 291 may reverse the rotation ofspindle 293, and thereby raising counter nut 294 relative to drive stem280. Movement of counter nut 294 away from contact with tool stem 260(FIG. 9B) allows rotation of drive stem 280 in the loosening directionto break up or loosen the connection between threaded coupling 266 andthreaded coupling 286.

FIG. 10 illustrates an alternative top drive system 300 according toembodiments described herein. Except as noted, top drive system 300 isconfigured and functions similarly to top drive system 100 and top drivesystem 200. For example, top drive system 300 includes a drive unit 310and a tool adapter 350. The drive unit 310 generally includes a housing320, becket 325, drive gears 330, motors 340, first portions of one ormore couplings 370, and a drive stem 380. Rather than torque sleeve 190or spindle unit 290, drive unit 310 includes a (torque) transmissionunit 390. Rather than actuators 191 or annular motor 291, drive unit 310includes a swivel 321 and a selection ring 395. The drive stem 380 mayextend through an interior of torque transmission unit 390 and aninterior of selection ring 395. At least a portion of swivel 321 may befixed relative to the housing 320, and swivel 321 may encircle drivestem 380. For example, swivel 321 may include a stationary portion 321-sthat is fixed relative to housing 320 and a rotatable portion 321-r thatmay rotate relative to housing 320. In some embodiments, the rotatableportion 321-r may be rotationally fixed to selection ring 395. Thestationary portion 321-s may encircle the rotatable portion 321-r. Drivestem 380 may have friction surfaces 387 that parallel and may engagewith friction surfaces 397 of transmission unit 390. The tool adapter350 generally includes a tool stem 360 and second portions of thecouplings 370. The tool stem 360 connects the top drive system 300 tothe tool string 2. The tool stem 360 and drive stem 380 may share acentral bore 365. When the drive unit 310 is coupled to the tool adapter350, top drive system 300 may transfer bi-directional torque, load,power, data, and/or signals between the top drive and the tool.

As illustrated in FIG. 11, transmission unit 390 generally includescouplings 370, one or more shoulders 394 proximate a bottom of thetransmission unit 390, one or more coupling holes 391 proximate a top ofthe transmission unit 390, and one or more friction surfaces 397. Thedrive stem 380 may extend through the interior of transmission unit 390.Friction surfaces 387 of drive stem 380 may parallel and may engage withfriction surfaces 397 of transmission unit 390. As illustrated, drivestem 380 includes eight disks projecting radially outward, each diskhaving two friction surfaces 387 (i.e., a top surface and a bottomsurface). As illustrated, transmission unit 390 has nine annular disksencircling drive stem 380 and interleaved with the eight disks of thedrive stem 380, each of the annular disks having one or two frictionsurfaces 397 (i.e., a top surface and a bottom surface). As would beunderstood by one of ordinary skill in the art with the benefit of thisdisclosure, other configurations of drive stem friction surfaces 387 andtransmission unit friction surfaces 397 may be considered to accommodatemanufacturing and operational conditions. Friction surfaces 387/397 maybe selectively engaged. For example, a transmission selector 393 (FIG.12) from selection ring 395 may be actuated (e.g., hydraulically) toapply a compressive (normal) force to the interleaved friction surfaces387/397. Engagement of friction surfaces 387 with friction surfaces 397may rotationally couple drive stem 380 with transmission unit 390. Alsoillustrated in FIG. 11, a portion of the exterior of drive stem 380 mayinclude a threaded coupling 386. Shoulders 394 may convey torque betweentransmission unit 390 and tool stem 360. As illustrated, shoulders 394may be disposed on an interior surface of transmission unit 390.Complementary shoulders 364 may be disposed on an exterior surface oftool stem 360 (FIG. 13A). The shoulders 394/364 may have guidingchamfers. It should be appreciated that other torque coupling typesand/or configurations may be considered to accommodate manufacturing andoperational conditions.

As illustrated in FIGS. 12A-12B, selection ring 395 includes one or morecoupling pins 396 engagable with coupling holes 391 of transmission unit390, one or more swivel selector 392 and one or more transmissionselector 393. The coupling pins 396 may be actuated (e.g.,hydraulically) to engage with coupling holes 391, thereby rotationallyfixing selection ring 395 with transmission unit 390. Each selector392/393 may be movable to an “on” position or an “off” position. Thedrive stem 380 may extend through an interior of selection ring 395.When swivel selector 392 is “on”, selection ring 395 may movesynchronously with stationary portion 321-s of swivel 321. For example,swivel selector 392 may include a pin that moves between an upperposition (FIG. 12A) and a lower position (FIG. 12B). When the pin ofswivel selector 392 is in the upper position, the swivel selector 392 is“on”, and selection ring 395 may move synchronously with stationaryportion 321-s of swivel 321. Likewise, transmission selector 393 mayinclude a pin that moves between an upper position (FIG. 12A) and alower position (FIG. 12B). Transmission selector 393 may engagetransmission unit friction surfaces 397 with drive stem frictionsurfaces 387. For example, transmission selector 393 may compresstransmission unit friction surfaces 397 against drive stem frictionsurfaces 387. When the pin of transmission selector 393 is in the lowerposition, the transmission selector 393 is “on”, and friction surfaces387 may engage with friction surfaces 397 to rotationally couple drivestem 380 with transmission unit 390. Likewise, when transmission unitfriction surfaces 397 are engaged with drive stem friction surfaces 387,rotation of drive stem 380 may transmit torque to transmission unit 390.It should be appreciate that coupling pins 396 will be engaged withcoupling holes 391 whenever transmission selector 393 is in the “on”position. Consequently, when the transmission selector 393 is “on”,selection ring 395 may move synchronously with transmission unit 390. Insome embodiments, swivel selector 392 and transmission selector 393 maybe a single unit. In some embodiments, swivel selector 392 and/ortransmission selector 393 may include or be actuated by a hydrauliccylinder. As would be understood by one of ordinary skill in the artwith the benefit of this disclosure, other configurations of swivelselectors 392 and transmission selectors 393 may be considered toaccommodate manufacturing and operational conditions.

In some embodiments, rather than coupling holes 391 in transmission unit390 and coupling pins 396 of selection ring 395, transmission unit 390may simply be fixed to selection ring 395. It should be appreciated thatcoupling holes 391 and coupling pins 396 may be beneficial formaintenance purposes.

As before, coupling of drive unit 310 to tool adapter 350 may proceed asa multi-step process. In one embodiment, illustrated in FIGS. 13A-13C,the coupling begins with axial load coupling between drive stem 380 andtool stem 360. Drive stem 380 may be aligned with tool stem 360 so thata lower portion of drive stem 380 may be stabbed into tool stem 360.Transmission unit 390 may also be aligned with tool stem 360 so thatshoulders 394 align with corresponding shoulders 364 on tool stem 360.For example, shoulders 394 may include concave features on an interiorsurface of transmission unit 390, while corresponding shoulders 364include convex features on an exterior surface of tool stem 360. In someembodiments, as illustrated in FIG. 12B, transmission selector 393 maybe initially moved to “on,” swivel selector 392 may be initially movedto “off,” and coupling pins 396 may engage coupling holes 391, so thatrotation of drive stem 380 may be used to align transmission unit 390with tool stem 360. Once transmission unit 390 is aligned with tool stem360, transmission selector 393 may then be moved to “off” to allow freerotation of drive stem 380 relative to transmission unit 390. Drive stem380 may rotate relative to tool stem 360 so that threaded coupling 386on drive stem 380 engage and mate with threaded coupling 366 on toolstem 360 (FIGS. 13B-13C). In some embodiments, transmission unit 390 mayremain fixed relative to housing 320 during axial load coupling. Forexample, swivel selector 392 may be set to “on” and coupling pins 396may engage coupling holes 391 during axial load coupling. Selection ring395 may thereby synchronize with stationary portion 321-s of swivel 321,which may be fixed relative to the housing 320. Likewise, transmissionselector 393 may be “off” during axial load coupling, so transmissionunit friction surfaces 397 may not be engaged with drive stem frictionsurfaces 387. Consequently, transmission unit 390 may not rotate withdrive stem 380 during axial load coupling.

Motors 340 may provide torque to make up or break out the axial loadconnection between tool stem 360 and drive stem 380. Torque of drivestem 380 may cause threading (or unthreading, depending on direction)between tool stem 360 and drive stem 380. Threaded coupling 386 of drivestem 380 may be RH male threading, while threaded coupling 366 of toolstem 260 may be RH female threading. When tool stem 360 is coupled todrive stem 380, as shown in FIG. 13C, axial load may be transferredbetween the top drive and the tool. Likewise, when tool stem 360 iscoupled to drive stem 380, central bore 365 may provide fluidcommunication between the top drive and the tool. When tool stem 360 iscoupled to drive stem 380, as shown in FIG. 13C, couplings 370 maycommunicate pneumatic, hydraulic, electrical, optical, or other powerand/or signals between drive unit 310 and tool adapter 350. In someembodiments, swivel 321 may provide torque to make up or break out thethreaded coupling 366. For example, a rotational actuator may be coupledbetween housing 320 and stationary portion 321-s of swivel 321.Stationary portion 321-s may not be rotationally fixed to housing 320,but may have some rotational freedom of movement (e.g., less than about60 degrees). In such embodiments, swivel 321 may be used as a wrenchingtong for make up if the motors 340 cannot apply sufficient torque.

Coupling of drive unit 310 to tool adapter 350 may proceed withbi-directional torque coupling between drive stem 380 and tool stem 360,as illustrated in FIGS. 13C-13E. Shoulders 394 on transmission unit 390may align and mate with corresponding shoulders 364 on tool stem 360. Itshould be appreciated that, immediately following axial load coupling,residual torque may exist in tool string 2. Drive stem 380 may counterthe residual torque while making-up threaded coupling 366 (FIGS.13B-13C). In some embodiments, drive stem 380 may be rotationallycoupled to transmission unit 390 following axial load coupling tofurther counter the residual torque. For example, transmission selector393 may be moved to “on,” while swivel selector 392 may remain “on,” andcoupling pins 396 may continue engage coupling holes 391 (FIG. 13D).Selection ring 395 may then safely switch from having swivel selector392 “on” (FIGS. 13A-13D) to having swivel selector 392 “off” (FIG. 13E).For example, residual torque may be transferred from tool string 2through tool stem 360 to shoulders 364, to shoulders 394, and totransmission unit 390. With transmission selector 393 “on,” swivelselector 392 “off,” and coupling pins 396 engaged with coupling holes391, selection ring 395 and transmission unit 390 may both rotationallysynchronize with drive stem 380. Drive stem 380 may thereby counter anyresidual torque from tool string 2. Likewise, once shoulders 394 matewith corresponding shoulders 364, and once transmission selector 393 is“on”, as shown in FIG. 13E, bi-directional torque may be transferredbetween the top drive and the tool. For example, torque may betransferred from the motors 340 through shaft 335 (not shown) to thedrive gears 330, to the drive stem 380, through the friction surfaces387/397 to the transmission unit 390, through the mated shoulders394/364 to tool stem 360, and to the tool string 2. Bi-directionaltorque may be thereby transferred from the motors 340 of the drive unit310 to the tool stem 360, and thus to the tool string 2.

In some embodiments, coupling drive unit 310 to tool adapter 350 may befacilitated with various sensors, cameras, actuators, couplers, and/oradapters. For example, signals and/or power may be transferred betweenthe rotatable portion 321-r of swivel 321 and the selection ring 395 byconnections 322 (FIG. 12). In some embodiments, swivel selector 392 andtransmission selector 393 are hydraulic cylinders, and connections 322may provide hydraulic control signals to swivel selector 392 andtransmission selector 393. As another example, signals and/or power maybe transferred between transmission unit 390 and tool stem 360 bycouplings 370.

As another example, coupling drive unit 310 to tool adapter 350 may befacilitated with sensors to detect misalignments between components. Forexample, in the illustrated embodiment, when swivel selector 392 is “on”(FIG. 13A), swivel selector 392 extends from selection ring 395 into arecess of swivel 321. Rotational misalignment of selection ring 395 andswivel 321 would not allow swivel selector 392 to extend from selectionring 395 into the recess of swivel 321. A sensor (e.g., an opticalsensor) may be disposed on an upper portion of selection ring 395 todetect orientation relative to swivel 321. Appropriate alignment ofselection ring 395 with swivel 321 may be achieved prior to actuatingswivel selector 392. As another example, transmission unit 390 may befirst oriented relative to tool stem 360 so that shoulders 394 alignwith shoulders 364. A sensor (e.g., an optical sensor) may be disposedat the base of transmission unit 390. The sensor may be configured todetect a marker (e.g., a reflector) disposed at the top of tool stem360. Transmission unit 390 may be rotated relative to tool stem 360until the sensor detects alignment with the marker. In some embodiments,multiple markers may be utilized. For example, transmission unit 390 maybe appropriately oriented in two or more orientations relative to toolstem 360. The sensor need only detect alignment with the first marker toidentify appropriate orientation of transmission unit 390 relative totool stem 360.

As another example, coupling drive unit 310 to tool adapter 350 may befacilitated with adapters to allow for slight misalignments betweencomponents. For example, connections 322 may include a retractableadapter that allows for slight misalignments. In some embodiments,adapters may allow for connection 322 to be made between the rotatableportion 321-r of swivel 321 and selection ring 395 even with slightrotational and/or positional misalignment. Once connection 322 has beenmade, the adapter may maintain connection 322 f while selection ring 395moves synchronously with swivel 321, even if a slight misalignmentdevelops.

As another example, coupling drive unit 310 to tool adapter 350 may befacilitated with remote control actuators. For example, swivel selector392 and/or transmission selector 393 may be remotely controlled.

It should be appreciated that, for each top drive system 100, 200, 300,other sensors, actuators, and/or adapters types and/or configurationsmay be considered to accommodate manufacturing and operationalconditions. The actuators may be, for example, worm drives, hydrauliccylinders, compensation cylinders, etc. The actuators may behydraulically, pneumatically, electrically, and/or manually controlled.In some embodiments, multiple control mechanism may be utilized toprovide redundancy. One or more sensors may be used to monitor relativepositions of the components of the top drive system. The sensors may beposition sensors, rotation sensors, pressure sensors, optical sensors,magnetic sensors, etc. In some embodiments, stop surfaces may be used inconjunction with or in lieu of sensors to identify when components areappropriately positioned and/or oriented. Likewise, optical guides maybe utilized to identify or confirm when components are appropriatelypositioned and/or oriented. In some embodiments, guide elements (e.g.,pins and holes, chamfers, etc.) may assist in aligning and/or orientingthe components of the top drive system 100, 200, 300. Bearings and sealsmay be disposed between components to provide support, cushioning,rotational freedom, and/or fluid management.

In an embodiment, a drive unit of a top drive system includes a drivestem having a torque gear profile and a load coupling, wherein the loadcoupling is a threaded coupling; and a torque sleeve movable between afirst position and a second position, and having a sleeve gear profilethat engages the torque gear profile when the torque sleeve is in thesecond position.

In one or more embodiments disclosed herein, the first position of thetorque sleeve is a raised position, and the second position of thetorque sleeve is a lowered position.

In one or more embodiments disclosed herein, the drive stem comprises adrive gear profile engagable with the motor.

In one or more embodiments disclosed herein, the drive stem extendsthrough an interior of the torque sleeve.

In one or more embodiments disclosed herein, the drive unit alsoincludes a swivel co-axial with the drive stem.

In one or more embodiments disclosed herein, the swivel is a hydraulicswivel.

In one or more embodiments disclosed herein, the drive unit alsoincludes an actuator configured to move the torque sleeve between thefirst position and the second position.

In one or more embodiments disclosed herein, the actuator is a hydrauliccylinder.

In one or more embodiments disclosed herein, the top drive system alsoincludes a tool adapter having a complementary load coupling to the loadcoupling of the drive stem, and a stem gear profile that iscomplementary to the sleeve gear profile.

In one or more embodiments disclosed herein, the top drive system alsoincludes at least one coupling between the drive unit and the tooladapter selected from a group consisting of: threaded couplings,hydraulic couplings, pneumatic couplings, electronic couplings, fiberoptic couplings, power couplings, data couplings, signal couplings,bi-directional torque couplings, axial load couplings, power couplings,data couplings, and signal couplings.

In an embodiment, a method of coupling a drive unit to a tool adapterincludes positioning the tool adapter below the drive unit; rotating adrive stem of the drive unit to make up a threaded coupling with a toolstem of the tool adapter; and moving a torque sleeve of the drive unitto engage both a torque gear profile of the drive stem and a stem gearprofile of the tool stem.

In one or more embodiments disclosed herein, moving the torque sleevecomprises moving the torque sleeve from a raised position to a loweredposition.

In one or more embodiments disclosed herein, the method also includesforming a coupling between the drive unit and the tool adapter, whereinthe coupling is selected from a group consisting of: threaded couplings,hydraulic couplings, pneumatic couplings, electronic couplings, fiberoptic couplings, power couplings, data couplings, signal couplings,bi-directional torque couplings, axial load couplings, power couplings,data couplings, and signal couplings.

In one or more embodiments disclosed herein, the method also includestransferring torque from the drive stem through the torque sleeve to thetool stem.

In one or more embodiments disclosed herein, the method also includestransferring axial load with the threaded coupling between the drivestem and the tool stem.

In an embodiment, a drive unit of a top drive system includes a drivestem having a load coupling that is a threaded coupling; a spindle unitcomprising: an interior through which the drive stem extends; a counternut having a first guide profile mated with a second guide profile onthe drive stem; and a spindle having threading mated with threading onthe counter nut; and an annular motor operationally coupled to thespindle unit.

In one or more embodiments disclosed herein, the annular motor comprisesa fixed portion that is fixed to the drive stem and a rotatable portionthat is rotatable relative to the drive stem.

In one or more embodiments disclosed herein, the rotatable portion isrotationally coupled to the spindle.

In one or more embodiments disclosed herein, the first guide profile ison an interior surface of the counter nut and the threading is on anexterior surface of the counter nut.

In one or more embodiments disclosed herein, the drive unit alsoincludes a motor, wherein the drive stem comprises a drive gear profileengagable with the motor.

In one or more embodiments disclosed herein, at least a portion of theannular motor is fixed relative to the drive stem.

In one or more embodiments disclosed herein, the top drive system alsoincludes a tool adapter having a complementary load coupling to the loadcoupling of the drive stem, and a shoulder proximate a top of the tooladapter.

In one or more embodiments disclosed herein, the top drive system alsoincludes at least one coupling between the drive unit and the tooladapter selected from a group consisting of: threaded couplings,hydraulic couplings, pneumatic couplings, electronic couplings, fiberoptic couplings, power couplings, data couplings, signal couplings,bi-directional torque couplings, axial load couplings, power couplings,data couplings, and signal couplings.

In an embodiment, a method of coupling a drive unit to a tool adapterincludes positioning the tool adapter below the drive unit; rotating adrive stem of the drive unit to make up a threaded coupling with a toolstem of the tool adapter; and rotating a spindle unit relative to thedrive stem to contact a counter nut of the spindle unit with the toolstem.

In one or more embodiments disclosed herein, the spindle unit remainsfixed relative to the drive stem while rotating the drive stem to makeup the threaded coupling.

In one or more embodiments disclosed herein, rotating the spindle unitrelative to the drive stem moves the counter nut vertically relative tothe drive stem.

In one or more embodiments disclosed herein, the method also includesforming a coupling between the drive unit and the tool adapter, whereinthe coupling is selected from a group consisting of: threaded couplings,hydraulic couplings, pneumatic couplings, electronic couplings, fiberoptic couplings, power couplings, data couplings, signal couplings,bi-directional torque couplings, axial load couplings, power couplings,data couplings, and signal couplings.

In one or more embodiments disclosed herein, the method also includestransferring bi-directional torque with the threaded coupling betweenthe drive stem and the tool stem.

In one or more embodiments disclosed herein, the method also includestransferring axial load with the threaded coupling between the drivestem and the tool stem.

In an embodiment, a drive unit of a top drive system includes a drivestem having first friction surfaces and a load coupling, wherein theload coupling is a threaded coupling; a transmission unit having: secondfriction surfaces parallel to the first friction surfaces; and shouldersproximate a bottom of the transmission unit; and a transmission selectormovable to an “on” position or an “off” position, wherein the drive stemmoves synchronously with the transmission unit when the transmissionselector is in the “on” position.

In one or more embodiments disclosed herein, the drive unit alsoincludes a swivel selector movable to an “on” position or an “off”position, wherein the transmission unit moves synchronously with aswivel of the drive unit when the swivel selector is in the “on”position.

In one or more embodiments disclosed herein, the swivel comprises astationary portion and a rotatable portion, and the swivel selectorcouples to the stationary portion.

In one or more embodiments disclosed herein, the drive unit alsoincludes a selection ring that includes the transmission selector.

In one or more embodiments disclosed herein, the selection ringcomprises coupling pins, and the transmission unit comprises couplingholes engagable with the coupling pins.

In one or more embodiments disclosed herein, the first friction surfacesare top and bottom surfaces of disks projecting radially outward on thedrive stem, and the second friction surfaces are top and bottom surfacesof annular disks encircling the drive stem.

In one or more embodiments disclosed herein, the top drive system alsoincludes a tool adapter having a complementary load coupling to the loadcoupling of the drive stem, and shoulders complementary to those of thetransmission unit.

In one or more embodiments disclosed herein, the top drive system alsoincludes at least one coupling between the drive unit and the tooladapter selected from a group consisting of: threaded couplings,hydraulic couplings, pneumatic couplings, electronic couplings, fiberoptic couplings, power couplings, data couplings, signal couplings,bi-directional torque couplings, axial load couplings, power couplings,data couplings, and signal couplings.

In one or more embodiments disclosed herein, the shoulders of thetransmission unit are on an interior surface of the transmission unit,and the shoulders of the tool adapter are on an exterior surface of atool stem of the tool adapter.

In an embodiment, a method of coupling a drive unit to a tool adapterincludes positioning the tool adapter below the drive unit so thatshoulders of a transmission unit of the drive unit align with shouldersof a tool stem of the tool adapter; and rotating a drive stem of thedrive unit to make up a threaded coupling with the tool stem, wherein:the drive stem and the transmission unit rotate together during thepositioning of the tool adapter; and the drive stem and the transmissionunit do not rotate together during the making up of the threadedcoupling.

In one or more embodiments disclosed herein, the method also includes,before making up the threaded coupling, moving a swivel selector to an“on” position to rotationally couple the transmission unit with ahousing of the drive unit.

In one or more embodiments disclosed herein, the method also includesrotating a portion of a swivel relative to the housing to wrench thethreaded coupling.

In one or more embodiments disclosed herein, the method also includes,after making up the threaded coupling, moving a transmission selector toan “on” position.

In one or more embodiments disclosed herein, the method also includes,after moving the transmission selector to the “on” position, moving aswivel selector to an “off” position.

In one or more embodiments disclosed herein, the method also includesforming a coupling between the drive unit and the tool adapter, whereinthe coupling is selected from a group consisting of: threaded couplings,hydraulic couplings, pneumatic couplings, electronic couplings, fiberoptic couplings, power couplings, data couplings, signal couplings,bi-directional torque couplings, axial load couplings, power couplings,data couplings, and signal couplings.

In one or more embodiments disclosed herein, the method also includestransferring torque from the drive stem to the transmission unit throughfrictional surfaces.

In one or more embodiments disclosed herein, the method also includesmating the shoulders of the transmission unit with the shoulders of thetool stem to transfer torque from the drive stem to the tool stem.

In one or more embodiments disclosed herein, the method also includestransferring axial load with the threaded coupling between the drivestem and the tool stem.

While the foregoing is directed to embodiments of the present invention,other and further embodiments of the invention may be devised withoutdeparting from the basic scope thereof, and the scope thereof isdetermined by the claims that follow.

The invention claimed is:
 1. A top drive system, comprising: a drive stem having first friction surfaces and a load coupling, wherein the load coupling is a threaded coupling; a swivel disposed about the drive stem; a transmission unit having: second friction surfaces parallel to the first friction surfaces; and shoulders proximate a bottom of the transmission unit; a transmission selector movable to an “on” position or an “off” position, wherein the drive stem moves synchronously with the transmission unit when the transmission selector is in the “on” position; and a swivel selector movable to an “on” position or an “off” position, wherein the transmission unit moves synchronously with the swivel when the swivel selector is in the “on” position.
 2. The top drive system of claim 1, wherein the swivel comprises a stationary portion and a rotatable portion, and the swivel selector couples to the stationary portion.
 3. The top drive system of claim 1, further comprising a selection ring that includes the transmission selector.
 4. The top drive system of claim 3, wherein the selection ring comprises coupling pins, and the transmission unit comprises coupling holes engagable with the coupling pins.
 5. The top drive system of claim 1, wherein the first friction surfaces are top and bottom surfaces of disks projecting radially outward on the drive stem, and the second friction surfaces are top and bottom surfaces of annular disks encircling the drive stem.
 6. The top drive system of claim 1, further comprising a tool adapter having a complimentary load coupling to the load coupling of the drive stem, and shoulders complimentary to those of the transmission unit.
 7. The top drive system of claim 6, further comprising at least one coupling between the transmission unit and the tool adapter selected from a group consisting of: hydraulic couplings, pneumatic couplings, electronic couplings, fiber optic couplings, power couplings, data couplings, signal couplings, bi-directional torque couplings, axial load couplings, and signal couplings.
 8. The top drive system of claim 6, wherein the shoulders of the transmission unit are on an interior surface of the transmission unit, and the shoulders of the tool adapter are on an exterior surface of a tool stem of the tool adapter.
 9. A method of coupling a drive unit to a tool adapter comprising: positioning the tool adapter below the drive unit so that shoulders of a transmission unit of the drive unit align with shoulders of a tool stem of the tool adapter; and rotating a drive stem of the drive unit to make up a threaded coupling with the tool stem, wherein: the drive stem and the transmission unit rotate together during the positioning of the tool adapter; and the drive stem and the transmission unit do not rotate together during the making up of the threaded coupling.
 10. The method of claim 9, further comprising, before making up the threaded coupling, moving a swivel selector to an “on” position to rotationally couple the transmission unit with a housing of the drive unit.
 11. The method of claim 10, further comprising rotating a portion of a swivel relative to the housing to wrench the threaded coupling.
 12. The method of claim 9, further comprising, after making up the threaded coupling, moving a transmission selector to an “on” position.
 13. The method of claim 12, further comprising, after moving the transmission selector to the “on” position, moving a swivel selector to an “off” position.
 14. The method of claim 9, further comprising forming a coupling between the drive unit and the tool adapter, wherein the coupling is selected from a group consisting of: threaded couplings, hydraulic couplings, pneumatic couplings, electronic couplings, fiber optic couplings, power couplings, data couplings, signal couplings, bi-directional torque couplings, axial load couplings, power couplings, data couplings, and signal couplings.
 15. The method of claim 9, further comprising transferring torque from the drive stem to the transmission unit through frictional surfaces.
 16. The method of claim 9, further comprising mating the shoulders of the transmission unit with the shoulders of the tool stem to transfer torque from the drive stem to the tool stem.
 17. The method of claim 9, further comprising transferring axial load with the threaded coupling between the drive stem and the tool stem.
 18. A of a top drive system, comprising: a drive stem having first friction surfaces and a load coupling, wherein the load coupling is a threaded coupling; a transmission unit having: second friction surfaces parallel to the first friction surfaces; and shoulders proximate a bottom of the transmission unit; a transmission selector movable to an “on” position or an “off” position, wherein the drive stem moves synchronously with the transmission unit when the transmission selector is in the “on” position; and a tool adapter having a complimentary load coupling to the load coupling of the drive stem, and shoulders complimentary to those of the transmission unit; wherein the shoulders of the transmission unit are on an interior surface of the transmission unit, and the shoulders of the tool adapter are on an exterior surface of a tool stem of the tool adapter.
 19. The top drive system of claim 18, further comprising: a swivel selector movable to an “on” position or an “off” position, wherein the transmission unit moves synchronously with a swivel when the swivel selector is in the “on” position.
 20. The top drive system of claim 19, wherein the swivel comprises a stationary portion and a rotatable portion, and the swivel selector couples to the stationary portion. 